A group of friends decided to divide the $800 cost of trip equally among themselves. When two of the friends decides not to go on the trip, those remaining still didvide the $800 cost equally , but each friends share of the cost increase by $20. How many friends were in the group orginally?

10 friends

Step-by-step explanation:

Let the initial number be x friends so that when 2 decide not to go, the remaining will be x-2. The final cost per person minus initial cost per person is $20.

Initial cost per person was

Final cost per person is

x=-8 or 10

Therefore, the original number was 10 friends

for any of you who need the translation here it is

step-by-step explanation:

find the angular size of the equatorial radius of the earth, if the horizontal parallax of the sun